Whether the result of putting petroleum on a child's dry, chapped skin and accidentally getting some on your child's hair, or simply a mischievous child who got into the Vaseline behind your back, Vaseline in the hair can be difficult to remove. Because of the petroleum jelly's greasy texture, washing the hair with shampoo can remove some of the residue but can leave the hair looking stringy and greasy. You'll need to blot away the excess and apply cornstarch to sop up the greasiness before removal.

Blot the hair with facial tissue to help sop up some of the greasiness, suggests HairBoutique.com. Just fold a facial tissue into quarters and press down lightly all over the hair until you see a visible improvement in the amount of Vaseline on the hair. Discard the tissues as soon as they get greasy and start a new one so you're not spreading greasiness around the hair.

Run a plastic fine-tooth comb through the sections of affected hair. This will remove some of the Vaseline that clings to the strands. After each pass, rinse the comb off the remove residue, says beauty website Beyond Jane. Continue combing until all of the obvious areas of Vaseline buildup are gone, and you're only left with a greasy residue.

Sprinkle cornstarch over the affected areas in your child's hair. Cornstarch will help to absorb the greasiness. Just add enough so the areas are covered with a light dusting of cornstarch, then pat the cornstarch into the hair so it absorbs the Vaseline. You can also use cornmeal for this step.

Wash the cornstarch out of your child's hair with a clarifying shampoo. This may mean using a more adult shampoo over your child's usual gentle, tear-free formula, so take care when you're washing and be careful to avoid your child's eyes. If you don't have a clarifying shampoo on hand, try washing your child's hair with liquid dish detergent, which strips the hair of excess oil to get it clean, recommends Fisher Price.